1. Field of the Invention
Exemplary embodiments of the present invention relates to an inflation device that is used for controlling the inflation of a balloon-tipped catheter. In more particular, the present invention relates to an improved inflation data display that provides an intuitive numeric and non-numeric representation of the inflation pressurization values to facilitate improved monitoring of balloon catheter inflation pressures. The present invention also relates to an improved modularized component assembly system for facilitating assembly of the inflation device apparatus.
2. Relevant Technology
Inflation syringes and catheter technologies have become increasingly important in the interventional radiology and cardiology medical fields. Balloon-tipped catheter systems and inflation syringe apparatus have been utilized in various fields of medicine, such as urology, gynecology, cardiology and others. One area in which balloon-tipped catheter systems and their associated syringe systems have resulted in significant improvement over traditional treatment methods is in connection with the treatment of coronary artery disease.
Coronary artery disease and the associated narrowing of the arteries that feed oxygen-rich blood to the heart (a condition known as “stenosis”) is one of the conditions for which balloon-tipped catheters are often utilized as a method of treatment. Traditionally, coronary artery blockages were treated with medicine or by performing coronary artery by-pass surgery. Various kinds of medication could be administered which would decrease the work of the heart by slowing the heart rate, dilating the blood vessels, or lowering blood pressure. However, such medicinal treatments did not cure coronary artery narrowing. As a result, not only would the arterial narrowing remain, but it would also continue to present a risk that at some point the narrowing would become serious enough to require surgical intervention.
In coronary artery by-pass surgery, a blood vessel from the chest or leg is grafted by passing the point of blockage so that the blood detours past the blockage in order to reach the heart. In some severe cases, multiple by-passes are performed. As is well known, coronary artery by-pass surgery is an expensive, highly invasive procedure which often requires prolonged hospitalization and recovery periods.
In the last several years, another method for treating coronary artery disease has developed, called balloon coronary angioplasty, or more technically, percutaneous transluminal coronary angioplasty (PTCA). PTCA is a much less traumatic procedure than coronary artery by-pass surgery. PTCA takes about two hours to perform and can be conducted under local anesthesia. PTCA has significantly improved patient recovery times allowing patients to resume normal activities in a matter of days. Because PTCA is much less expensive and less traumatic than by-pass surgery while still providing effective blockage removal, PTCA has experienced a dramatic increase in the number of such procedures performed each year.
To perform a typical PTCA procedure, an introducer sheath is inserted through an incision made in the groin of the patient or in the artery of an arm of the patient. An x-ray sensitive dye is injected into the coronary artery through a catheter that is introduced through the sheath. The dye enables the doctor, through the use of real-time x-ray technology, to clearly view the patient's vasculature on a television monitor and to thereby locate the blockage. A balloon-tipped catheter is advanced through the vasculature to the point of the blockage with the help of the x-ray monitor.
Due to the increase in the number of PTCA procedures being performed, there has been a substantial increase in the use of electronically monitored inflation syringe systems which are utilized to inflate the balloon catheter or other inflatable balloon-type device during PTCA procedures. Typical syringe systems comprise a barrel and a plunger which are selectively operable to increase fluid pressure applied to the balloon catheter and to remove the applied pressure to the balloon catheter once the procedure is finished. The syringe systems are adapted to provide user readable feedback to the practitioner in the form of a numeric value allowing the practitioner to assess the amount of pressurization that is being applied to the balloon. This allows the practitioner to closely monitor pressurization values to provide a more controlled and systematic inflation of the balloon during the procedure.
Many of the apparatus utilized in PTCA procedures are inexpensive devices which can be discarded after a single use. Disposable devices eliminate expensive and time consuming sterilization procedures which are necessary for reusable devices. Moreover, disposable devices eliminate the risk of transmission of diseases between patients. Consequently designers and manufacturers of inflation syringes have worked to limit the expense of such disposable inflation syringes to make them more cost-effective for a wide variety of applications. As a result, there has been an emphasis in favoring more simple designs over more complex apparatus. Such designs typically comprise a simple digital or analog readout of the inflation pressure on the display provided in connection with the inflation syringes.
One typical display of electronically monitored syringes comprises a 7-segment LED display having three to five fields, and perhaps a decimal point. Such simplistic displays are limited in the information they can convey. Some displays provide only the current pressurization of the syringe. Higher-end models may allow the user to toggle the display to view additional information. Although the ability to view additional information can be useful, the user is required to expend mental effort and time to access the additional information, interpret the relevance of the data, and determine how the different values interrelate. Still more expensive syringes may have multiple 7-segment LED displays so as to display multiple values simultaneously. Yet, even with multiple values displayed, a user expends time and mental effort to interpret and relate the values, and to remember which displays represent given values.